This application is based on and claims the benefit of priority from prior Japanese Patent Application No. 2001-289862, filed on Sep. 21, 2001, the entire content of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a paper web feeder for a rotary press, which comprises a rotary shaft rotatably supported by a pair of support frames opposing to each other; support arms provided in plural and radial about the rotary shaft for supporting a paper web rotatably at each arm tip; rotary conduction means located at a displaceable angle associated with rotation of the rotary shaft; stationary conduction means secured on the pair of support frames; and connection means for electrically connecting the rotary conduction means to the stationary conduction means.
2. Description of the Related Art
In such the paper web feeder, it is often required to supply an electric current between the rotary shaft and an electric device that is provided on radial support arms for supporting webs of paper attached on the rotary shaft. In this case, it is publicly known to employ, for example, a mechanism that includes a slip ring provided on the rotary shaft and a brush contacted with the slip ring (see JP 38-9668B publication).
In this mechanism, an electric wire extending from the slip ring to the electric device is, for example, installed through a narrow space between a support frame and radial support arms as shown in FIG. 5. In a conventional paper web feeder Axe2x80x2 shown in FIG. 5, a pair of support frames 37, 38 are employed to rotatably support a rotary shaft 30, which is provided with web supports Exe2x80x2 for supporting paper webs Qxe2x80x2. The rotary shaft 30 is also provided with a pair of support arms 31, 32, each composed of three arms arranged in radial at an equal angular interval about the rotary shaft 30 or in a three-forked shape.
At an appropriate location on the support frame 37, for example, on the outer side of the frame 37, a controller Fxe2x80x2 is provided to control operations of the web supports Exe2x80x2. On parts of the rotary shaft between the support frame 37 and the support arm 31 and between the support frame 38 and the support arm 32, a connection means Dxe2x80x2 is provided, respectively, which comprises a slip ring mechanism consisting of a slip ring and a brush (not depicted).
This connection means Dxe2x80x2 employs a slip ring and a brush for electrically connecting an electric wire, which displaces in angle associated with rotation of the rotary shaft 30, with an electric wire, which extends from the controller Fxe2x80x2 and is secured on the support frame 37 (38), to make conduction between them. In the connection means Dxe2x80x2, the slip ring opposes and contacts to the brush. The slip ring is provided in coaxial with the rotary shaft 30 on the outer surface of the rotary shaft 30 to rotate integrally with the rotary shaft 30. The brush is secured on the inner surface of the support frame 37 (38).
A cable 33 (34), which is a rotary connection means Bxe2x80x2, wired from the web support Exe2x80x2 is connected to the slip ring. A cable 35 (36), which is a stationary connection means Cxe2x80x2, wired from the controller Fxe2x80x2 is connected to the brush.
In the conventional paper web feeder Axe2x80x2, however, the connection means Dxe2x80x2 is provided on either or both parts of the rotary shaft between the support frame 37 and the support arm 31 and between the support frame 38 and the support arm 32. In this case, due to the narrow location space for the connection means, it is extremely difficult to execute a maintenance operation for the connection means Dxe2x80x2 if any malfunction occurs in the connection means Dxe2x80x2. Further, if the need for replacement of the connection means arises, a large-scale operation is required, for example, to remove the rotary shaft 30 from the support frames 37, 38.
In addition, automatization of the paper web feeder requires many electric devices to be located on the support arms 31, 32. Consequently, it is required to provide an increased number of connection terminals on the connection means Dxe2x80x2 for electrically conducting these many electric devices to the stationary conduction means Cxe2x80x2. For example, if the connection means Dxe2x80x2 is a slip ring mechanism, it is required to increase the number of slip rings and brushes for configuring the connection terminals, resulting in a wider space required for the connection means Dxe2x80x2. If a gap between the support frames 37 and 38 is widened, a gap between bearings for the rotary shaft 30 is also widened. This increases an amount of flexure of the rotary shaft 30, losing stability in the web support, and inviting a delay in the automatization of the paper web feeder.
The present invention has an object to provide a paper web feeder, which allows easy operations of maintenance and replacement to be achieved on occurrence of a malfunction. In addition, even if the number of wires is increased and connection means is up-sized due to expanded functions of support arms, no influence is given to bearings in support frames for a rotary shaft.
To achieve the above object, the present invention is provided with a paper web feeder for a rotary press. The paper web feeder comprises a pair of support frames opposing to each other; a rotary shaft rotatably supported by the pair of support frames; support arms provided in plural and radial about the rotary shaft for supporting a paper web rotatably at each arm tip and configured to rotate integrally with the rotary shaft; rotary conduction means located at a displaceable angle associated with rotation of the rotary shaft for conducting to an electric device, the electric device displacing in angle associated with rotation of the rotary shaft; stationary conduction means secured on either of the pair of support frames and conductive to the rotary conduction means; and connection means for electrically connecting the rotary conduction means to the stationary conduction means. The rotary shaft has axial ends, at least one of the axial ends protruded outside from the pair of support frames. The rotary shaft also has a hollow portion formed therein extending from a mid-portion between the pair of support frames to the portion protruded outside from the pair of support frames. The stationary conduction means and the connection means are provided outside the pair of support frames. The rotary conduction means has a portion extended through the hollow portion to outside the pair of support frames and electrically connected to the connection means.
As obvious from the above, in the paper web feeder according to the present invention, the stationary conduction means and the connection means are provided outside the pair of support frames. Therefore, when a malfunction occurs in the connection means, its maintenance and replacement can be easily performed. In addition, no connection means is provided in between the support frame and the support arm. Therefore, it is possible to narrow a gap between the bearings in the pair of support frames for the rotary shaft.
Preferably, in the paper web feeder according to the present invention, the mid-portion of the rotary shaft between the pair of support frames and the portion protruded outside from the pair of support frames each have at least one opening formed therein for communicating with the hollow portion to introduce the rotary conduction means through the opening to inside and outside the hollow portion.